Man, this whole topic is the 3rd rail of Knowledge Work politics... But here's my $0.02 on a rainy Saturday afternoon.
America exists because it is a nation of Immigrants, moreso than any other country in history. People WANT to come here and build a new life. Except for some notable, tragic exceptions (slavery, refugees from wars which we started), folks from all over the world (not just former colonies) have self-selected to come here It's what makes this country strong and - dare I write it - exceptional. We'd be incredibly stupid to cut that pipeline off.
At the same time, our immigration system is horribly broken and is regularly abused by both the immigrants and us natives. I won't go into examples except to say truly think about how that $2 head of lettuce at the grocery store got into your refrigerator. However, the H1B program is actually NOT abused, at least relatively speaking. Simply put, Hiring an H1B worker is a tremendous pain-in-the-keister - there are quotas per-company, there are a ton of HR and USCIS hoops to jump thru, etc. You, the employer must prove that you are unable to hire an equivalent US-native worker, and that you will pay same salary to the H1B worker. Yes, there are dodges around those rules, but generally not worth it. The REAL abuse of the system is the L1A and L1B programs, intra-company transfers. That's were you see companies bring in employees from their "foreign branch office" (often just a shell) to literally take your job. Worse yet when they are multi-national consultants, and yes, I will name names - Tata Consulting, Infosys, ant their ilk. And it's no picnic for the actual "consultants" being sent over, they basically live in indentured servitude for 6 months or a year then get kicked back home. Anyway, it's a very broken system.
Back to H1B. As the original poster pointed out, you have to really know your stuff to get an H1B visa. One of the solutions to our immigration crisis that constantly being bandied about is - including by our recent occupant of the White House - is that we have skills-based immigration. Like in Canada, Australia, New Zealand, to name a few. Well, it's that what H1B visa is doing, in a ham-handed way? I'd argue that we are getting the advantage of the best and brightest coming to work here. And treating them quite shabbily, at least Canada, etc, you know you are on a path for citizenship. Here you are - again - essentially an indentured servant.
Summing up, I'm not saying that all H1B folks are paragons of virtue, untapped geniuses, etc. Many are, many are not. And the entire system is ripe for abuse from all sides. But if you want to do something about it, then engage yourself - write to your congress-creature, get out and vote. speak up at work, speak with your H1B colleagues, ask "Why is there no-one hireable for this position here in the US?," and truly open your mind. Honestly, there are no easy answers, but start your actions with the thought - We ARE a nation of Immigrants.